Programmable control systems generally contain a run-time system for the timed sequence control of an automation component, a machine or a system, and an engineering system for compiling and editing control programs. The project or project engineering data developed in the engineering system are transferred into the run-time system and used to output the controlled variables. Furthermore, the run-time system taps off current values from the automation component to be controlled and, directly or after buffering in a data store belonging to the run-time system, makes them available to the engineering system. By means of the engineering system, the current values provided can be analyzed and, if necessary, an intervention in the control program is possible.
Typically, status information is output on the run-time system which permits the user to draw conclusions about the state of the control of the automation component. Information which goes beyond the pure operation and observation of the system is generally not displayed on the run-time system. Information of this type is frequently evaluated only when detailed knowledge about the control software is available. As a rule, only service personnel have this detailed knowledge. In order to tap-off such detailed service and diagnostics data, the service personnel use the aforementioned engineering system, with which the control software can then be modified in accordance with the result of the analyzed data. It is therefore necessary for the service personnel to tap-off the detailed diagnostics data from the run-time system on site by means of an engineering system, and to make appropriate changes to the control program.